Mattress size guide
Selecting the perfect mattress tailored to your unique sleep needs is an undeniably important decision for your bedroom. UK mattress sizes vary significantly, with widths and depths engineered to complement your bed frame. To give you clarity, Louise Silver, our Product Technologist, has curated this mattress size guide, offering a definitive mattress size chart and expert guidance on the different bed sizes available.
Last Modified 13 May 2026 |
First Added 17 August 2019
Written by Louise Silver
A quick note on bed sizes
To bring clarity to your planning, we’ve outlined the standard bed dimensions in order of scale. While the internal sizes of mattresses are standardised, the footprint of your bed frame varies based on its size. For a comprehensive look at how different frames affect your space, explore our buyer’s guide to beds.
| Bed size | Centimetres | Feet and inches |
| SMALL SINGLE | 75 x 190 cm | 2’3" x 6’3" |
| SINGLE | 90 x 190 cm | 3'0" x 6’3" |
| SMALL DOUBLE | 120 x 190 cm | 4'0" x 6’3" |
| DOUBLE | 135 x 190 cm | 4’6" x 6’3" |
| KING | 150 x 200 cm | 5'0" x 6’6" |
| SUPER KING | 180 x 200 cm | 6'0" x 6’6" |
| EMPEROR | 200 x 200 cm | 6’6" x 6’6" |
Bespoke comfort starts here: A mattress sizing masterclass
The size of a small single bed and mattress
The small single mattress size measures 75cm wide by 190cm long. These precise dimensions serve as a sophisticated solution for restrictive layouts, offering a transitional foundation for growing children. Despite its narrower silhouette, it maintains the same resolute support found in our larger scales.
What size is a single mattress?
For a standard solo sleeper, the single mattress dimensions of 90cm wide by 190cm long represent the traditional choice. This size of mattress remains the definitive standard for children as they navigate the transition into adolescence, providing ample room for restorative sleep. To ensure everyday ease, Louise Silver advocates for a high-quality non-turn mattress in this size, offering enduring comfort and steadfast support without the need for regular flipping.
Small double bed (Queen Size) dimensions
The small double mattress size, often referred to as a Queen, measures 120cm wide by 190cm long. This size is best suited to an individual sleeper who desires an active landscape to move. While it can accommodate two adults for occasional use, we recommend a double bed size for regular shared use. This size pairs particularly well with Ottoman or Divan frames, where space efficiency is a physical need.
The dimensions of a double mattress
The standard double mattress size of 135cm x 190cm remains a cornerstone of British homes. It provides a balanced harmony for two sleepers, though it offers each individual just 67.5cm of width. The measurements of a double mattress suit if you are seeking intimacy or are navigating the compact proportions of a smaller bedroom space.
From a technical perspective, adds Louise, "the double is a high-utility size. However, research cited by the National Bed Federation indicates the average person adjusts their position 60 to 70 times a night. In a double bed, those movements are more likely to disrupt your partner's neutral alignment."
The transition: Double vs king-size mattresses
When evaluating a double vs a king-size mattress, consider both the length and the width. King bed dimensions extend to 200cm, providing a buoyant surface for those over 6ft tall. This upgrade is not merely about space; it’s about the physics of comfort. A king-size mattress offers 17% more total sleeping area than a double. This buffer zone is vital for thermal regulation, allowing air to circulate more freely between sleepers - a physical benefit that prevents the overheating common in smaller, more restricted spaces.
"When learning how to measure a mattress for your needs, you must take body measurements into consideration," notes Louise Silver. "To avoid protrusion at the foot of the bed, your mattress should be at least 10cm longer than the tallest person. For this reason, a king bed size is the definitive choice for anyone over 6ft."
King-size bed and mattress measurements
The king-size mattress dimensions of 150cm wide by 200cm long offer a significant elevation in comfort. This scale provides an additional 15cm of width and 10cm of length compared to a standard double, creating an abundant surface that accommodates a more intuitive sleep posture.
This increase in surface area is technically significant; it allows each sleeper an additional 7.5cm of personal geography, which is often the critical margin required to prevent motion transfer between partners. By providing this buffer, a king-size mattress ensures that the micro-movements of one sleeper do not disrupt the neutral alignment of the other.
The size dimensions of a super king bed and mattress
The super king bed dimensions of 180cm wide by 200cm long offer an expansive landscape for those who prioritise the luxury of unrestricted movement. This size provides each sleeper with the equivalent space of a standard single bed, giving you independence that minimises night-time disruption. These generous super king mattress dimensions also accommodate the modern family dynamic, providing ample room for children or pets to join for shared morning moments. If you are navigating the finer nuances between these options, our King vs Super King guide offers the technical breakdown needed to decide.
What size is an emperor mattress?
The emperor mattress size represents the pinnacle of our definitive range, measuring a significant 200cm wide by 200cm long. As the biggest size mattress available, it offers an unrivalled sense of individual opulence and a weightless repose that is second to none. The Emperor is the architectural choice for grand primary suites, designed if you refuse to compromise on personal sleep space.
Mattress depth and the visual appeal
Beyond length and width, standard mattress depth is a critical technical spec that influences both comfort and the visual balance. An average mattress depth typically ranges between 20cm and 30cm, but luxury builds often reach an extra-deep profile of 35cm or more.
"Think of mattress depth like a bellows," explains Louise. "The volume and layers within the internal architecture manage the air and movement within the mattress. However, when selecting an extra deep mattress, be mindful of the visual ratio. We advocate that a minimum of 50cm of the headboard should remain visible above the mattress and pillows. This ensures the headboard maintains pride of place."
For a clear and considered choice, explore our chart below to help you find the perfect fit:
|
Mattress Depth |
Measurement |
Overview |
|
Average depth |
8-12 inches |
Balanced and versatile, offering a refined level of comfort with a lighter overall profile. |
|
Deep |
12-20 inches |
Light and accessible. Higher profiles offer better comfort and longevity than slimmer styles. |
|
Extra Deep |
20+ inches |
Grand, cocooning and traditional in feel – with a more substantial profile. |
|
Pillow Top |
Varies (An added top layer) |
Adds height and comfort without the weight of a full, extra-deep mattress. |
Surface tension and base support
The choice of base dictates the final result. A slatted base offers yielding support, whereas a platform-top divan will make any standard-size mattress feel significantly firmer. We advocate for sprung slats to enhance the intuitive response of our spring systems. Beyond the scale and base, you should also consider how firmness impacts your neutral alignment; our mattress firmness guide provides deeper clarity.
Bedroom planning
While standard mattress sizes are fixed, the physical presence of your bed is dictated by its frame. A sleigh bed or an upholstered frame with a winged headboard can add up to 20cm of length to the total footprint.
When planning your bedroom, always measure for the frame’s outer silhouette to ensure a minimum of 60cm remains clear on all three open sides. This space allows for the intuitive movement and ensures your bedside furniture remains practical rather than disruptive.
For those looking to create an even more balanced environment, our feng shui bedroom guide offers principles on furniture placement and energy flow.
The flexibility of zip & link mattresses
Narrow dimensions in British stairwells often pose a challenge for those seeking a super-king or emperor-size bed. Louise endorses the zip & link mattress as a definitive solution. This architecture involves two independent mattresses that zip together, allowing for effortless installation in rooms with restricted access. It also permits split tension - allowing one sleeper a firm foundation while the other enjoys a more yielding response.
Ensuring a seamless installation
Beyond the proportions of your bedroom, it’s vital to consider the path through your home. While your chosen standard-size mattress may fit perfectly within its intended sanctuary, it must first navigate the physical restrictions of your space.
Before finalising your selection, we advise you to measure a mattress path with precision. Document the height and width of all doorways, the vertical clearance of stairwells, and any narrow corridors. To ensure a resolute delivery, remove all temporary obstructions - such as floor lamps or curated wall art - along the route. For more in-depth advice on avoiding unexpected complications when your biggest bed size arrives, please consult our comprehensive delivery & access guide.
Your mattress is an investment in repose
The right-sized mattress is the first step toward a more restorative existence. Once you have made your selection, protecting that investment is paramount; our mattress care guide details the definitive maintenance steps for years to come.
We invite you to experience our mattress range by visiting one of our showrooms. Secure your investment in rest and create a sanctuary that is as steadfast as it is elegant.